OpenEDX Custom Theme Creation

We are looking to create a custom theme for OpenEDX platform following some template themes/website. Need the package css, html files in line with the OpenEDX standards for theme creation hosted at:

https://edx.readthedocs.io/projects/edx-installing-configuring-and-running/en/open-release-eucalyptus.master/configuration/changing_appearance/theming/index.html